;--------------------------------------------------------------------------
;  crt0.s - Generic crt0.s for a Z80
;
;  Copyright (C) 2000, Michael Hope
;
;  This library is free software; you can redistribute it and/or modify it
;  under the terms of the GNU General Public License as published by the
;  Free Software Foundation; either version 2, or (at your option) any
;  later version.
;
;  This library is distributed in the hope that it will be useful,
;  but WITHOUT ANY WARRANTY; without even the implied warranty of
;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;  GNU General Public License for more details.
;
;  You should have received a copy of the GNU General Public License 
;  along with this library; see the file COPYING. If not, write to the
;  Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
;   MA 02110-1301, USA.
;
;  As a special exception, if you link this library with other files,
;  some of which are compiled with SDCC, to produce an executable,
;  this library does not by itself cause the resulting executable to
;  be covered by the GNU General Public License. This exception does
;  not however invalidate any other reasons why the executable file
;   might be covered by the GNU General Public License.
;--------------------------------------------------------------------------

    .module crt0
    .globl  _main

    .area   _HEADER (ABS)
    .org    0x100

init:
    ;; Set stack pointer below BDOS
    ld      sp,(0x0006)

    ;; Initialise global variables
    call    gsinit
    call    _main
    jp      _exit

    ;; Ordering of segments for the linker.
    .area   _HOME
    .area   _CODE
    .area   _INITIALIZER
    .area   _GSINIT
    .area   _GSFINAL

    .area   _DATA
    .area   _INITIALIZED
    .area   _BSEG
    .area   _BSS
    .area   _HEAP

    .area   _CODE

_exit::
    jp      0x0000

    .area   _GSINIT
gsinit::
    ld      bc, #l__INITIALIZER
    ld      a, b
    or      a, c
    jr      Z, gsinit_next
    ld      de, #s__INITIALIZED
    ld      hl, #s__INITIALIZER
    ldir
gsinit_next:

    .area   _GSFINAL
    ret
